Predicting response to Botox (or rather, a similar product, Myobloc)

A recently published study by neurologists at the Military Medical Center in San Antonio led by Dr. Grogan tried to find predictors of response to botulinum toxin injections in chronic migraine sufferers. They looked at the records of 128 patients who received injections of botulinum toxin, although they did not receive Botox (onabotulinumtoxinA), but a similar product, Myobloc (rimabotulinumtoxinB). It has been previously reported (and mentioned in this blog) that patients with headaches who experience constricting pain or pain in the eye are more likely to respond than those who have an “exploding” headache or pain with pressure felt going from inside out. This new study confirmed this observation, originally made by Dr. Rami Burstein and his colleagues at Harvard Medical School. Dr. Grogan and his colleagues’ patients received an average of 7 and a half treatments over a period of 22 months. Treatment results showed that 80% of their patients who received injections of Myobloc had at least a 50% improvement and 57% had a greater than 75% reduction in their headache frequency. This is similar to the 70% response rate we see with Botox injections. Patients who had migraine with aura were more likely to respond to Myobloc injections. Just like with Botox side effects were few and mild and only 4% of patients decided to stop this treatment due to side effects. More patients who received Myobloc (82%) complained of pain during injections. I have also observed this and the reason is that Myobloc is very acidic, while Botox is non-acidic.
There are two other botulinum toxin products on the market, but only Botox is approved by the FDA for the treatment of chronic migraine headaches. These other two products are Dysport (abobotulinumtoxinA) and Xeomin (incobotulinumtoxinA) and they are more similar to Botox than Myobloc because they are also type A botulinum toxins, while Myobloc is type B. Only Botox is approved by the FDA for the treatment of chronic migraine headaches, while the other three are approved for movement disorders such as dystonia as well as for cosmetic use.

You may want to argue with your insurance company that although only Botox is approved for chronic migraines, Myobloc is actually cheaper than Botox, so they would save money. You can also add that you have antibodies to Botox and that is why it doesn’t work. I’ve had patients who stopped responding to Botox and the insurance did agree to pay for Myobloc. Most likely, your doctor has to make this argument on your behalf.

C. Barnes says: 07/10/20158:21 am

My Neuro was using myobloc on me for my chronic migraines and it was very effective. Then my insurance company decided they wouldn’t pay for it anymore and I’ve switched to Botox. It is not working nearly as well for me. I’m not happy at all about this.

Dr. Mauskop says: 10/16/20149:51 am

In the rare event when Botox injections result in the development of antibodies, the botulinum toxin that might work is Myoblock. Myoblock is a different type of toxin – type B, while Xeomin and Dysport are type A, just like Botox.

Sue says: 10/16/20149:40 am

Do you ever use Dysport or Xeomin in your patients that have stopped responding to Botox. My son responded the first two times to Botox but had not response the last two treatments. He will have another treatment, but I’m wondering if he has developed antibodies to Botox and should try Dysport or Xeomin. If you have used either of the other two, how much do you use (units) for migraine, and do you inject in the same locations as the Botox. Thanks–

Kathy says: 08/18/20149:11 pm

THANKS for this article. I had to go back to Botox because the doctors that are at the Neurology clinic I go to are not able to give Myobloc, but my 2 Neurologist prior were able (but they were Army docs and transfered since) I have more migraines this time, and I’m not sure if it’s because the Botox would almost be like starting over again, but before I started on Myobloc (like almost EVERY OTHER Rx) the Botox wasn’t as effective. Myobloc STINGS and BURNS going in (but WORTH IT in the end) I believe my new Doc will have to have me see a Specialist someone on Oahu, and I had heard from the headache specialist who I had before who could do the Myobloc about the other 2 drugs, but not sure if they have the drug or not and they mentioned new things were coming out. I’m hoping there will be something that will help me feel like my NON migraine days…

Dr. Mauskop says: 03/20/20134:08 pm

There have been no studies comparing follow-the-pain vs fixed (same for everyone) protocol of Botox injections. The FDA-approved way to inject Botox for chronic migraines is the fixed protocol, which calls for every patient with chronic migraines to receive 31 injections with 155 units of Botox. Botox manufacturer, Allergan, is required by the FDA to train doctors using only this fixed protocol because it was used in two large double-blind studies (I participated in one of them) that led to the approval of Botox by the FDA. However, just like with any other medication, doctors are allowed to modify the way they utilize Botox. In your case it should not matter since forehead is included in the fixed protocol and, if that is where you have pain, should be also injected by a doctor who may want to use follow-the-pain approach.

Did the study, or any other that you know of, speak about the specific areas of injection for the Botox (or other medication)? Mr neurologist stands by a pericranial approach, as opposed to focusing on the sites of pain, such as the forehead.
Thank you.